US 12,224,669 B2
Flyback power converter and secondary-side control method thereof
Chung-Wei Lin, Hsinchu County (TW); Hung-Ching Lee, Hsinchu County (TW); and Tzu-Chen Lin, Hsinchu County (TW)
Assigned to Leadtrend Technology Corp., Hsinchu County (TW)
Filed by Leadtrend Technology Corp., Hsinchu County (TW)
Filed on Jan. 31, 2023, as Appl. No. 18/104,260.
Claims priority of provisional application 63/320,707, filed on Mar. 17, 2022.
Prior Publication US 2023/0299682 A1, Sep. 21, 2023
Int. Cl. H02M 3/335 (2006.01); H02M 1/32 (2007.01); H02M 1/36 (2007.01)
CPC H02M 3/33507 (2013.01) [H02M 1/32 (2013.01); H02M 1/36 (2013.01); H02M 3/33592 (2013.01)] 22 Claims
OG exemplary drawing
 
11. A flyback power converter with secondary-side control, comprising:
a primary-side controller, comprising:
a first gate control signal generation circuit for generating a first gate control signal;
a trigger pulse detection circuit for receiving a first voltage; and
a start-up circuit coupled to the trigger pulse detection circuit and the first gate control signal generation circuit, wherein after the primary-side controller enters a start-up mode, the start-up circuit generates a first control signal to the first gate control signal generation circuit at a first predetermined valley of the first voltage, and the first gate control signal generation circuit generates the first gate control signal to turn on a power switch according to the first control signal; and
a secondary-side controller, comprising:
a voltage detection signal generation circuit coupled to an output terminal of a second side of the flyback power converter;
a valley detection circuit for receiving a second voltage; and
a second gate control signal generation circuit coupled to the voltage detection signal generation circuit and the valley detection circuit, wherein after the valley detection circuit detects a first coupling voltage corresponding to the first gate control signal on the second voltage, the second gate control signal generation circuit generates a trigger pulse to a synchronous switch at a second predetermined valley of the second voltage to make the primary-side controller enter a secondary-side control mode from the start-up mode.